The first hybrid powertrain prototype of McLaren’s new Ultimate Series flagship, the Speedtail, begins a yearlong global test regime that will underpin the development of the first McLaren Hyper-GT.

The test program will see Speedtail prototypes running in Europe, North America and Africa, initially at automotive test facilities but later in traffic on public roads.

Production of the £1.75 million ($2.25 million) Speedtail is to commence at the end of 2019, with first deliveries in early 2020.

McLaren calls it the fastest, most aerodynamic and most luxurious model it has ever made. Only 106 will be produced and all of them already are allocated to owners.

Echoing the naming of development test mules of its legendary forebear, the 1992 McLaren F1, the Speedtail prototype has been christened Albert.

The Speedtail has a production-specification chassis and gasoline-electric hybrid drivetrain, as well as a unique three-seat cockpit with central driving position.

During development and validation every aspect of the Speedtail’s performance will be honed as its 1,050 hp propels the prototype to 250 mph (403 km/h).

The testing includes high-speed trials with Kenny Bräck, McLaren chief test driver and former IndyCar champion, at the wheel.

Ben Gulliver, McLaren head of vehicle development, says the start of real-world testing represents a major step in the development of the Speedtail.

“As the first fully representative prototype, Albert will build on the invaluable work still being put in by earlier development cars, allowing us to sign off vehicle attributes including chassis dynamics, brake performance, damper tuning, tires, NVH and aspects of ergonomics and comfort,” he says.

The Speedtail’s center-seat layout was first publicly demonstrated in a proof-of-concept model that was a McLaren 720S reconfigured with a single, centrally mounted driving seat.

Four further mules followed, and these will continue to be used around the world for performance and durability testing alongside the prototype vehicles.

Despite its test livery and the bodywork from the A-pillars forward, Albert is fundamentally a Speedtail, with shape-representative body panels and dihedral doors around the carbon-fiber McLaren Monocage core structure.

The production-level specification allows Speedtail attributes to be proven in real-world conditions early in the development process.